Pure practical reason is the opposite to impure (or sensibly-determined) practical reason and appears in Immanuel Kant's Groundwork of the Metaphysics of Morals.
It is the reason that drives actions without any sensible incentives. Human reasoning chooses such actions simply because those actions are good in themselves; this is the nature of good will, which Kant argues is the only concept that is good without any justification, it is good in itself and is a derivative of a transcendental law which affects the way humans practically reason (see practical philosophy).
Famous quotes containing the words pure, practical and/or reason:
“In a pure society, the subject of marriage would not be so often avoided,—from shame and not from reverence, winked out of sight, and hinted at only; but treated naturally and simply,—perhaps simply avoided like the kindred mysteries. If it cannot be spoken of for shame, how can it be acted of? But, doubtless, there is far more purity, as well as more impurity, than is apparent.”
—Henry David Thoreau (1817–1862)
“The cycle of the machine is now coming to an end. Man has learned much in the hard discipline and the shrewd, unflinching grasp of practical possibilities that the machine has provided in the last three centuries: but we can no more continue to live in the world of the machine than we could live successfully on the barren surface of the moon.”
—Lewis Mumford (1895–1990)
“The best reason why Monarchy is a strong government is, that it is an intelligible government. The mass of mankind understand it, and they hardly anywhere in the world understand any other.”
—Walter Bagehot (1826–1877)